Fuel burners



Dec. 9, 1958 G. w. JACKSON ET AL FUEL BURNERS Filed Dec. 1, 1955INVENT'ORS GEORGE I4. JACKSON W/LL/AM G. DAUGHERTY BY a 1 ATTORNEYS FUELBURNERS George W. Jackson and William G. Daugherty, Salt Lake City, UtahApplication December 1, 1955, Serial No. 556,298

3 Claims. (Cl. 15874) This application is a continuation in part of ourprior application for Fuel Burners, Serial No. 291,691, filed June 4,1952.

This invention relates to improvements in fuel burners which may beapplied to any suitable or desired heating appliance, either for spaceheating, power purposes or other applications. It may be used in smallunits of home heating size or of much larger sizes adapted forindustrial installation.

Oil burners have come into extensive commercial use both for homeheating and for industrial installations. Nevertheless, the type of oilburners usually employed are very inefficient and while many attemptshave been made to improve the efliciency thereof, these have not beenvery satisfactory. Attempts have been made to supply water to the oilburner for producing ordinary steam therein to atomize the fuel oil.Most available water supplies contain some minerals which, in theordinary system using water or steam supplied to the oil burner, willcause the coil or burner to clog up in a short time with a mineraldeposit out of the Water.

One object of this invention is to improve the construction of fuelburners, especially oil burners, to provide greater efiiciency and morecomplete combustion of the fuel, thereby requiring much smallerquantities of fuel for a given output of heat or power.

Another object of the invention is to provide in a fuel burner for asubstantially constant high temperature and high B. t. 11. content.

A further object of the invention is to provide a fuel burner which isrelatively small and inexpensive to con struct and to operate and whichis compact and practical for manufacture and for use either as homeheating size or for industrial installation.

Still another object of the invention is to provide more completecombustion of all combustible particles of the fuel, thereby reducing toa minimum if not to an absolute zero the discharge flue gases andvisible smoke.

These objects may be accomplished according to one embodiment of theinvention by the construction of a burner having provision for atomizingliquid fuel into a stream of superheated steam and air which arecombined before the introduction of the fuel thereto. A coil or othersteam heating unit is associated with the burner in position to besubjected to the heat of the burner. Steam is supplied to this coil orother unit under a pressure of approximately 90 pounds preferably and issuperheated therein to a temperature of the order of 1,000" F. to 1500F. although higher temperatures can be used if materials are availableto withstand such higher tempera tures without appreciabledeterioration.

This superheated steam is then directed into the burner jet around atube and is discharged at high velocity into a mixing chamber where itis mixed with air at one end of this tube and is carried along into thecombustion zone by the high vacuum or suction created in the burner. Theliquid fuel is dropped or atomized into this mixture of air andsuperheated steam and is carried thereby be Fatented Dec. 9, 1958 yondthe end of the jet before combustion takes place. The combustion of theburner continues to maintain a supply of superheated steam to the burnerproducing complete combustion of the fuel and high efficiency ofoperation as will be explained hereinafter.

This embodiment of the invention is illustrated in the accompanyingdrawings in which:

Fig. 1 is a perspective view partly broken away and in section showingthe burner construction;

Fig. 2 is a longitudinal section through the burner partly inperspective; and

Fig. 3 is a cross section through the discharge nozzle showing adistributing ring in place therein.

The fuel burner illustrated as an embodiment of this invention includesa main jet assembly generally indicated by the numeral 1. This jetassembly 1 is shown as axially disposed within the burner constructionalthough if several such jet assemblies be required, these may bedisposed around the axis in spaced relation to' each other.

The jet assembly 1 is directed toward a combustion chamber which may beformed in any suitable manner according to the use of the burner. Thecombustion chamber may be provided by a surrounding wall of refractorymaterial or other suitable material and in the illustrated embodiment isshown as enclosed by a surrounding housing generally indicated at 2,being of cylindrical form merely as an example. The housing 2 projectsoutwardly from a front cover construction indicated generally at 3 andwhich is provided with a face plate 4 on the side thereof toward thehousing 2. The face plate 4 has an enlarged opening 5 therein in whichthe burner assembly 1 is located and directed and which opening 5 alsoserves to supply secondary air to the interior of the combustion chamber2. The front cover 3 is provided with an enlarged opening 6 in thebottom thereof for admitting air into the cover both for supplyingprimary air and also for supplying secondary air to the burner.

The burner assembly is illustrated more in detail in Fig. 2. This burnerassembly includes an enlarged housing 7 closed at one end by a head 8and at the opposite end by a nozzle 9. These parts may be screw threadedtogether as shown or otherwise secured in rigid relation to each other.

The head 8 has a tapered center opening 14) therein within which ismounted a tube 11, one end of which is secured rigidly to the head 8 andthe tube is supported thereby. The tube 11 extends into telescopedrelation with a mixing chamber 12 formed in the center of the nozzle 9,and surrounded by a sleeve 13 formed in the nozzle. The nozzle in turnhas a liquid. fuel atomizing chamber 14 surrounding the sleeve 13.

The chamber 14 is partially closed at the discharge side of the nozzle 9by a closure ring 15 that is secured to the nozzle by welding or inother suitable manner.

, The inner faceof the closure ring 15 is tapered complementary to thetapered end of the sleeve 13, providing a discharge slot 26 therebetweensurrounding the mixing chamber 12 through which the fuel is dischargedinto the stream of mixed steam and air as hereinafter described.

Fuel is supplied to the chamber 14 through a coupling I receivesuperheated steam from the interior of the body 7 for mixing with oil orother liquid fuels supplied through a pipe 22 from the main oil supply19. A control valve 1 in detail.

is. shown at 23 for regulating the supply of liquid fuel through thepipe 22. The auxiliary jet 21 may be of conventional construction, ifdesired, and is not described This auxiliary jet is directed into'thecombustion chamber adjacent the jet assembly 1 to preventbackdraft fromcausing the flame. to be deflected, or causing the jet assembly to goout. This will not be required in any instance where such. back-draft isnot encountered and may be omitted, if desired.

The interior of the body 7 is enclosed as a steam chamber which hascommunicationthrough a passage between the inner end of the. nozzle 9and the discharge end of the tube 11' into the mixing chamber 12.Superheated steam is thus supplied from. the'chamber 24 into the mixingchamber and is mixed with air that is directed through the tube 11 intosaid mixing chamber. This occurs before the liquid fuel is dischargedinto the mixed stream at the slot 16.

The chamber 24 is connected through a steam supply pipe 26 with a steamsuperhea'ting unit generally indicated at 2 7 inFig. 1-. In thisembodiment of the invention, steam may be supplied from a steamgenerator at about 90 lbs. pressure.

A pilot burner is shown at w which may be supplied with natural gas,butane, propane or the like through a conduit 31. This burner is shownas mounted on the face plate for directing a frame into the combustionchamher for initial ignition of the burner assembly.

In the event that the liquid fuel should not be dis tributed uniformlyaround the periphery of the mixing chamber 12 at the slot 16, adistributing ring 32 may be mounted in the atomizing chamber 14. A metalring is used for this purpose and is telescoped over the sleeve 13substantially as shown in Fig. 3. The ring 32 preferably is somewhatflattened in the lower segment thereof and throughout about the lowerone-half thereof tapering from a full circular cross section tosubstantially a semicircular cross section. This ring has been found toaid the distribution of the liquid fuel around the entire chamber 14,thus obtaining better supply thereof to the mixture of airandsuperheated. steam.

Operation When it is desired to start theoperation of the burner, thesteam pipe 28 may be initially closed by the valve 29 and liquid fuelsupplied through the pipes 18 and 22 to the jet assemblies l. and 21. Asmall supply of steam may be admitted through the pipe '28 to thechamber 24 and mixing chamber 12 to aid inatornization of the liquidfuel in the initial burning process. The pilot burner 30 is started toproduce a flame in the combustion chamber and to cause burning of theatomized fuel discharged from the jet assembly 1.

When the jet assembly is operating sufdciently to heat the coils 27 to asubstantial extent, the supply of steam may be turned on or increasedand the operation of the burner will then proceed.

We prefer to use 90 pounds of steam pressure on the line 28 to give thevelocity needed. During normal operation of the burner, the steam thatis supplied to the coil 27 should be heated to a temperature of 1000 F.to 1500 F. and may be increased still more if materials are availablewhich will withstand such higher temperatures. We prefer to usestainless steel or Monel metal in forming the coil or other superheatingelement.

This superheated steam is supplied from the steam chamber 24 through theopening 25 into the mixing chamber 12. A high velocity of steam is usedpreferably about 209 feet per second in movement through the mixingchamber 12 which will create a suction through the tube 11 to drawprimary air in from the front cover assembly anclthe opening 6 therein.This high velocity steam and air mixture will be forced through themixing chamber into-the combustion zone at such velocity that combustioncapnot talgeplacein theregion of the nozzle 9 of the jet assembly, butcombustion will occur appreciably spaced from the jet assembly in theregion of the coil 27. The latter may be placed at or adjacent the pointof highest combustion as desired and according to the materialsavailable for the construction of the coil. A very high temperature Willbe generated in the normal operation of the burner and the coil must notbe too close to that area so as to cause disintegration thereof.

The liquid fuel is dropped into the stream of moving steam and air atthe very vortex of the jet assembly and substantially at the dischargeend of the latter. Thus, the liquid fuel does not come into contact withthe superheated steam to any appreciable extent within the jet assemblyitself. The high velocity movement of the steam and air will carry thefuel outward from the jet assembly before any combustion could takeplace. This high velocity movement will create a low pressure area atthe dis charge side of the jet assembly and the liquid fuel isdischarged into this area.

We do not understand fully the physics of the action that takes placewithin the burner, but it is our belief that the high velocity ofmovement through the burner and the high temperature of the superheatedsteam causes the water molecules in the steam to break down into theirhydrogen and oxygen atoms which aids hydrogenation of the fuel bycombining the hydrogen atoms with the carbon atoms of the fuel andutilizing the oxygen to aid combustion.

We have conducted extensive individual and comparison tests with thisburner and with other available oil burners, and these have revealed thevery superior qualities of this burner and have demonstrated its abilityto operate under the more eflicient operation as herein set forth.

This improved fuel burner achieves complete combustion of oil regardlessof weight. unburned fuel to smoke or pollute the air. This is especiallyimportant where smoke ordinances are in effect. At the same time only asmall amount of air is required for complete combustion and no blowersare needed even on the largest models, thus resulting in additionalsavings of cost of installation and of operation. It has beendemonstrated that the burner uses only approximately fifty percent ofthe amount of fuel of other comparable burners, and moreover that muchless costly fuels are required, of lower grades and yet full efficiencyis obtained.

The burner does not require any forced draft. The test has shown only8.71% excess air average over four hour periods with 15% CO This meansthat the stack temperature will be kept low and that only a vent pipewill suffice for disposing of spent products, thus reducinga major itemof expense in construction.

The operation of the. burner is very simple. no moving parts to wearout. A long life is assured with constant operation and few servicecalls. Where the burner is employed in industrial installations, this isespecially important, not .only because it minimizes the man hoursrequired for maintenance but also because it eliminates to a substantialextent shut-down of the plant. There is no problem of carbon or sootdeposits that must becleaned out as required in many other burners.

It Will be understood that the manually controlled valves can bereplaced, if desired, by automatically 0on trolled valves and otherautomatic controls used as found desirable.

While the invention has been illustrated and described in oneembodiment, it is also recognized that variations and changes maybe madetherein without departing from the invention as set forth in the claims.

We claim:

l. A fuel burner comprising an elongated hollow body, ahead closing oneend of the body, a nozzle having an openjende'd mixingchambe r thereinclosing the other end'of the body, an open-ended relatively small Thereis no wasted or There are air tube within said body and extending fromsaid head to the inner end of the mixing chamber, the space in said bodyaround the air tube forming a relatively large steam chamber having asuperheated steam inlet thereto, said steam chamber at its inner endhaving restricted opening means surrounding said air tube for thedischarge of steam into the inner end of the mixing chamber, saidenlarged steam chamber providing for a large residue of superheatedsteam substantially to preheat the column of air in said relativelysmall air tube, said noz- Zle having a fuel chamber with a fuel inlettherein surrounding said mixing chamber, said fuel chamber havingrestricted opening means surrounding the mixing chamber at the outer endthereof for the discharge of fuel thereto, whereby steam passing fromsaid steam chamber through said steam discharge means will cause avacuum in said air tube drawing air therein and will mix with the air inthe mixing chamber and air and steam passing out of said mixing chamberwill draw fuel out to the discharge end of the mixing chamber.

2. A fuel burner comprising an elongated hollow body, a head closing oneend of the body, a nozzle having an open-ended mixing chamber thereinclosing the other end of the body, an open-ended relatively small airtube within said body and extending from said head to the inner end ofthe mixing chamber, the space in said body around the air tube forming arelatively large steam chamber having a superheated steam inlet thereto,said steam chamber at its inner end having restricted opening meanssurrounding said air tube for the discharge of steam into the inner endof the mixing chamber, said enlarged steam chamber providing for a largeresidue of superheated steam substantially to preheat the column of airin said relatively small air tube, said nozzle having a fuel chamberwith a fuel inlet therein surrounding said mixing chamber, said fuelchamber having restricted opening means surrounding the mixing chamberat the outer end thereof for the discharge of fuel thereto, adistributing ring in said fuel chamber substantially coplanar with theaxis of said fuel inlet whereby steam passing from said steam chamberthrough said steam discharge means will cause a vacuum in said air tubedrawing air therein and will mix with the air in the mixing chamber andair and steam passing out of said mixing chamber will draw fuel out tothe discharge end of the mixing chamber.

3. A fuel burner comprising a combustion chamber, a coil in thecombustion chamber, means for supplying steam to said coil forsuperheating therein, an elongated hollow body in said combustionchamber, a head closing one end of the body, a nozzle having anopen-ended mixing chamber therein closing the other end of the body, anopen-ended relatively small air tube within said body and extending fromsaid head to the inner end of the mixing chamber, the space in said bodyaround the air tube forming a relatively large steam chamber having asuperheated steam inlet thereto communicating with said coil, said steamchamber in its inner end having a restricted opening means surroundingsaid air tube for the discharge of steam into the inner end of themixing chamber, said enlarged steam chamber providing for a largeresidue of superheated steam substantially to preheat the column of airin said relatively small air tube, said nozzle having a fuel chamberwith a fuel inlet therein surrounding said mixing chamber, said fuelchamber having a restricted opening means surrounding the mixing chamberat the outer end thereof for the discharge of fuel thereto, wherebysteam passing from said steam chamber through said steam discharge meanswill cause a vacuum in said air tube drawing air therein and will mixwith the air in the mixing chamber and air and steam passing out of saidmixing chamber will draw fuel out to the discharge end of the mixingchamber.

References Cited in the file of this patent UNITED STATES PATENTS403,963 Shallow May 28, 1889 474,344 Ramsay May 3, 1892 719,801 HoldenFeb. 3, 1903 726,059 Henley Apr. 21, 1903 999,165 Herpin July 25, 19111,403,954 Herpin Jan. 17, 1922 1,434,324 Boudreaux Oct. 31, 19221,448,802 Hoffman Mar. 20, 1923 1,457,000 Park May 29, 1923 1,554,141Terry Sept. 15, 1925 1,611,067 Prosser Dec. 14, 1926 1,685,967 SullivanOct. 2, 1928

